The transport (TCP, UDP, etc.) target port number for this protocol, i.e., an alternate port from the protocol default, or zero if not specified (use protocol default). This object MAY be used for any print protocol (from the Internet, NetWare, AppleTalk, or other protocol suite). If this object is zero, then the actual target port number is the default port for the specified 'ppmPortProtocolType' (e.g., 'chPort9100(11)' uses '9100'). If this object is non-zero, then it SHOULD NOT conflict with the default (e.g., IANA-registered) target port implied by the value of 'ppmPortProtocolType' or the explicit transport target port specified in 'ppmPortServiceNameOrURI'. In case of conflict, the URI value in 'ppmPortServiceNameOrURI' is authoritative (e.g., 'ipp://example.com:631/~smith/printer'). If 'ppmPortProtocolType' is 'chLPDServer(8)', then this object MUST be ignored (because LPR target port is fixed at '515').